Assessment of genetic variability in low land sub1 introgressed rice genotypes showing tolerance to submergence and stagnant flooding

The present investigation is carried out to establish the nature of relation between grain yield and yield components by partitioning the correlation coefficients between grain yield and its components into direct and indirect effects by using simple correlation and path analysis .By the help of correlation coefficients Selection index were constructed to increase the selection efficiency .A correlation coefficient and path analysis study was conducted in 51 low land Rice with tolerance to submergence and stagnant flooding for ten component characters including grain yield. The results indicated that grain yield was positively correlated with days to flowering, plant height, fertile grain number and fertility percentage indicating the importance of such traits for realization of high yield in rice. The traits like days to 50% flowering exhibited maximum positive direct effect on grain yield followed by plant height, grain yield per plant, fertility percentage and 100-grain weight, thus, indicating the importance of such traits as criteria for selection for realization of higher productivity. Using grain yield as economic criterion, ten selection indices were constructed. On the basis of selection criteria, the promising genotypes selected were IR 85086-SUB 33-3-2-1, IR 88760-SUB 93-3-3-3, Upahar, IR 88250-20-1-1-3, Jagabandhu, IR 88230-60-1-2-2, CR1009 sub 1, IR 87092-26-3-1-3, Savitri, IR 87098-55-2-1, Mahanadi, PSBRc 68, Swarna, Swarna-sub 1, PSBRc 70. evaluation of sub 1 introgressed line in normal condition i.e. how the sub 1 lines are performing without the occurrence of flood. The genotypes like savitri-sub 1, IR 64-sub 1 , PSBRc 18- sub1 , IR 85086-SUB 33-3-2-1, IR 87439-BTN-145-2-1, IR 88228-33-3-5-2, IR 88234-STG 11-1-1-1, IR 88250-20-1-1-3, IR 88764-SUB 30-1-1-2 and IR 88776-SUB 8-1-1-2 had shown high level of submergence tolerance through screening under control conditions.